This plate allows an SFX PSU to be mounted in the hole for an ATX PSU.
Print the plate.
Drill out the inner 3 holes using a 0.138 inch diameter drillbit.
Tap the outer 4 holes with a 6-32 tap. (I have found taping is unecessary)
This plate is altered from stock SFX to match "CIT Micro Atx Power Supply". Stock SFX needs a width of 100, not 125.
I have added reinforcing ridges around the outside.